Looking for a little boost down the stretch, the Diamondbacks have added 22-year-old Jarrod Parker to the relief corps in advance of Monday’s game.

Parker, who missed the entire 2010 season following Tommy John surgery, returned to go 11-8 with a 3.79 ERA and a 112/55 K/BB ratio in 130 2/3 innings for Double-A Mobile this year. He struggled with control problems early, but he improved to a 2.84 ERA and a 56/22 K/BB ratio in 69 2/3 innings in the second half.

It’ll likely be a very temporary bullpen stint for Parker. He may need some Triple-A time at the beginning of next year, but it shouldn’t be long before he’s a fixture in the Arizona rotation. First, he’ll try to impress enough in the next 10 days to force the team to carry him on the postseason roster.

Paxton, 30, has been among the game’s better starters over the past few years. In 2018, he went 11-6 with a 3.76 ERA and a 208/42 K/BB ratio in 160 1/3 innings. The lefty has two more years of arbitration eligibility remaining after earning $4.9 million this past season.

Sheffield, 22, is the headliner in the Mariners’ return. He made his major league debut in September for the Yankees, pitching 2 2/3 innings across three appearances. Two of those appearances were scoreless; in the third, he gave up a three-run home run to J.D. Martinez, certainly not an uncommon result among pitchers. MLB Pipeline rates Sheffield as the Yankees’ No. 1 prospect and No. 31 overall in baseball.

Thompson-Williams, 23, was selected by the Yankees in the fifth round of the 2016 draft. This past season, between Single-A Charleston and High-A Tampa, he hit .299/.363/.546 with 22 home runs, 74 RBI, 63 runs scored, and 20 stolen bases in 415 plate appearances. He was not among the Yankees’ top-30 prospects, per MLB Pipeline.

Swanson, 25, was selected by the Yankees in the eighth round of the 2014 draft. He spent most of his 2018 campaign between Double-A Trenton and Triple-A Scranton/Wilkes-Barre. Overall, he posted a 2.66 ERA with a 139/29 K/BB ratio in 121 2/3 innings. MLB Pipeline rated him No. 22 in the Yankees’ system.

This trade comes as no surprise as the Yankees clearly wanted to upgrade the starting rotation and the Mariners seemed motivated to trade Paxton this offseason. To the Mariners’ credit, they got a good return for Paxton, as Sheffield likely becomes the organization’s No. 1 prospect. The only worry about this trade for the Yankees is how Paxton will fare in the more hitter-friendly confines of Yankee Stadium compared to the spacious Safeco Field. The Yankees are likely not done adding, however. Expect even more new faces before the start of spring training.